When the paths of a motorized vehicle and an other road user such as a pedestrian or cyclist cross, the other road user often must decide whether to cross in front of the approaching vehicle. This decision may involve the other road user observing the approaching vehicle to gauge its speed and whether it is maintaining an approximately constant speed, accelerating, or decelerating. Based on those observations, the other road user can decide whether there is sufficient time for the other road user to cross safely.
A vehicle can output a signal of some kind to indicate to an other road user that the vehicle is about to accelerate or decelerate to assist the other road user in deciding whether to cross or wait. Such a signal can be particularly helpful in the case of an approaching autonomous vehicle, in which there might not be an attentive human occupant to gesture to the other road user. However, other road users might hesitate to trust such a signal from an autonomous vehicle.